The kits, which cost about $450 each, contain global positioning devices and accelerometers, which measure movement in three directions: up/down, left/right, and front/back. Every time a car travels over a road anomaly, the accelerometer records the depth and width of the hole, sending the data to CarTel’s website with geographic coordinates when it passes a wireless access point at MIT or elsewhere.

Applications built on top of this system can collect, process, deliver, analyze, and visualize data from sensors located on mobile units such as automobiles. A small embedded computer on the car interfaces with a variety of sensors in the car, processes the collected data, and delivers it to an Internet server.

Commute and traffic portal: A Web site that shows all the trips made by a driver and makes personalized route recommendations based on the driver’s own history as well as the aggregate driving history of other drivers with information along common paths. The portal provides interesting ways to visualize one’s trips, and tools to analyze this data.

MyRoute: CarTel’s rich data set obtained from GPS-equipped cars enables us to model delays observed on various road segments as statistical distributions.

Fleet testbed, a 27-car CarTel deployment in the cars of a local limo company (PlanetTran). This testbed also serves as the “vehicle” for much of our research, allowing us to deploy software and applications on a running system (in addition, some user’s cars also have CarTel nodes).

CafNet (“carry and forward network”) protocols that will allow cars to serve as data mules, delivering data between nodes that are otherwise not connected to one another. For example, these protocols could be used to deliver data from sensor networks deployed in the field to Internet servers without requiring anything other than short-range radio connectivity on the sensors (or at the sensor gateway node).

Unlike traditional automotive telematics systems that rely on cellular or satellite connectivity, CarTel uses wireless networks opportunistically. It uses a combination of WiFi, Bluetooth, and cellular connectivity, using whatever mode is available and working well at any time, but shields applications from the underlying details.